The trouble with tools is getting the most out of them. It helps to learn how to use them properly. A hammer is pretty simple to get a hang of, but how many of us really know how to program our VCR. I’m dating myself here. Even though I can remember a day before VCRs, I do have a DVD player and I’d go as far as to say I know how to burn a DVD too. So this month I thought I’d explain some of those letters on the dial on top your camera. Even though I’m one of the few men that reads a camera manual, I know that most people don’t get very far in theirs. It’s not very interesting reading and the language is down right dry. So I’m going to try and help you out here.

The letters I’ll talk about are what are called the shooting modes.

You are going to be telling your camera what kind of photos you are going to be taking by what letter you select on your dial. These let you control the two things that determine exposure, aperture or f-stop and shutter speed. Aperture is the iris in the lens that lets a measured amount of light into the camera and shutter speed is how long the picture is exposed. Generally speaking modern cameras do a pretty nice job of getting the exposure right and there is much less guesswork about exposure than there used to be. So let’s tackle the letters: My Nikon camera has the letters P, S, A, and M, although Canon cameras use the letters TV and AV in place of Nikon’s S and A respectively.

P stands for program.

In program mode your camera selects the proper f-stop and shutter speed by a preset formula. When there is enough light you are provided a small enough f-stop for good depth of field (what’s going to be sharp in the final picture) and fast enough shutter speed to stop any camera shake. As you start losing light for a proper exposure your camera will start opening up the f-stop and slowing down the shutter speed by the same preset formula so you end up with a properly exposed picture. When the light really starts falling off you start ending up with pictures that are blurry because the shutter speed is so slow you can’t hold your camera still enough during the exposure and the image lacks depth because the f-stop is open all the way making a flat lifeless image. Beginners might want to start with program mode until you start understanding how the whole depth of field thing works.

S or Canon’s TV stands for shutter speed priority

When you start breaking away from program mode and want to stop action you will select these letter(s). Say you are at a sports event and want to stop the action of the players. You now have the ability of selecting a fast enough shutter speed to do so and still know the camera will select the proper f-stop for a good exposure. The photographers at NFL football games all have their cameras set at shutter speed priority. A rule of thumb for hand-holding a shot is that the shutter speed should be faster than the focal length of the lens. For example if you are shooting with a 200mm lens your shutter speed should be 1/200 of a second or faster. This is because the longer the lens is, the more exaggerated the movement from the camera will be.

A or AV means aperture priority

When you start needing to control what is going to be rendered as sharp in your final image you start paying attention to what aperture you select. An old photojournalist was once asked how he got such great pictures. He replied, “f8 and be there” Now f8 is an aperture with enough depth of field to create an image that has good depth and sharpness. The sharpest part of a lens (optically) is usually near the middle of their f stop range. On most lenses f8 is near the middle of that scale. In aperture priority you select the f stop you desire and the camera selects the proper shutter speed for a good exposure, just the opposite of shutter speed priority. I usually have my camera set to aperture priority for two reasons: First I’m using a tripod so I don’t really care what the shutter speed is. My camera is being held rock solid. Second, more than anything, I want to know what’s going to be sharp in my photographs. One of the most distracting part of some photographs I see is out of focus areas that shouldn’t be. I often use f stops of 22 or 32 especially with a wide angle lens.

M stands for manual

In this mode you select both the shutter speed and f stop and determine the exposure by the information the camera tells you. My first SLR camera was a totally manual camera. It let me make all kinds of mistakes like an automatic camera can never do. A person would choose manual mode when the camera’s exposure is being fooled by difficult lighting or they want to purposely over or under expose their photograph. I use manual in the studio because I use a flash meter to determine my exposure and I don’t want any surprises from the camera.

I hope this clears up a few thoughts about what those letters mean.

Gene Rodman is a life long photographer and owns Montana Photographic Arts Gallery and Studio. You can view his website at http://www.MTPhotoArts.com.